Sleeping In On Weekends Giving You A Case Of The Mondays: Study

There may be actually be science behind that dreaded "case of the Mondays."

What exactly is causing the start-of-the-week sluggishness? A phenomenon known as "social jet lag," or the shift in workers’ sleep patterns that takes place between regular weekdays and the weekend.

Even minor shifts in people’s sleep schedules during the weekend, such as staying up late and sleeping in, can have an impact on workers' memory and reaction times, according to researchers from Rush University in Chicago, (h/t The Daily Mail). The change in sleeping patterns may also explain that groggy feeling come Monday morning. The study found that test subjects' reaction times to a bullseye on a screen were slower in the mornings than they were in the evenings, especially following a weekend of sleeping in.

The study, which also found that the effects of social jet lag can last until Wednesday and, over time, contribute to heavier use of caffeine and increased chance of obesity, isn’t the first to describe the negative effects of the phenomenon. The term was first coined by German Professor Till Roenneberg who also found that workers with increased levels of social jet lag were three times more likely to be overweight. Increased odds of drinking during the weekend, odd meal times and staying up later to socialize can all contribute to social jet lag.

But workers may recover more quickly from social jet lag than the Rush study finds, at least according to bosses. Multiple surveys have found that Tuesday is the most productive day of the week.